Force governing door hinge

ABSTRACT

A DOOR HINGE FOR GOVERNING THE FORCE REQUIRED TO ROTATE A DOOR UPWARDS ABOUT AN AXIS HAVING A HORIZONTAL COMPONENT. A NEGATOR SPRING CREATES A CONSTANT FORCE ON THE DOOR MEMBER. THE FORCE DUE TO THE NEGATOR SPRING AIDS THE MOMENT DUE TO THE WEIGHT IF THE DOOR AND ACTS THROUGH A MOMENT ARM THAT VARIES INVERSELY WITH THE MOMENT CREATED BY THE WEIGHT IF THE DOOR WITH RESPECT TO THE AXIS OF ROTATION. THE MOMENT ARM THROUGH WHICH THE NEGATOR SPRING ACTS THE MOMENT ARM OF THE WEIGHT OF THE DOOR ARE DIRECTLY DEPENDENT UPON THE LATERAL DEVI-   ACTION OF THE CENTER OF GRAVITY OF THE VERTICAL ALIGNMENT WITH THE AXIS OFF ROTATION.

Nov. 23, 1971 DI NOIA ETAL 3,621,508

FORGE GOVERNING DOOR HINGE Filed Oct. 5, 1970 2 2 r %0 45 II 40 I7 3| 6 4| 3| 43 v 'w 7 GD/ 2 39 I K a 34 .P 44 12 4 C) K 637? FIG! K K' 3Q 28 9 29 2 4e 7 24 23 3]\X l 22 x; 25

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H //Vl/E/VTOR$= 6 3 Emanuel J. Di/Vo/a Theodara R. Braunich Henry B. K/aha \N (Hay.

United States Patent O 3,621,508 FORCE GOVERNING BOOR HINGE Emanuel J. Di Noia, Briar Cliff Manor, and Henry B.

Klatte, Yonkers, N.Y., and Theodore R. Breunich,

Stamford, Conn., assignors to Universal Oil Products Company, Des Plaines, Ill.

Filed Oct. 5, 1970, Ser. No. 77,943 lint. Cl. E05f 1/12 US. Cl. 16-180 6 Claims ABSTRACT OF THE DISCLOSURE A door hinge for governing the force required to rotate a door upwards about an axis having a horizontal component. A negator spring creates a constant force on the door member. The force due to the negator spring aids the moment due to the weight of the door and acts through a moment arm that varies inversely with the moment created by the weight of the door with respect to the axis of rotation. The moment arm through which the negator spring acts and the moment arm of the weight of the door are directly dependent upon the lateral deviation of the center of gravity of the door from vertical alignment with the axis of rotation.

This invention relates to a door hinge for governing the force required to rotate a door member upwards about an axis having a horizontal component. More particularly, a negator spring creates a constant force on the door member. The force due to the negator spring aids the moment due to the weight of the door and acts through a moment arm that varies inversely with the moment created by the weight of the door with respect to the axis of rotation. The moment arm through which the negator spring acts and the moment arm of the weight of the door are directly dependent upon the lateral deviation of the center of gravity of the door from vertical alignment with the axis of rotation.

This invention is primarily applicable to doors that rotate upward about a horizontal axis, although the invention finds utility in a door that rotates upward about an axis having any horizontal component. Doors that operate in this manner are Widely used for a number of different applications. Overhead storage compartments in aircraft, garage doors, and overhead storage compartments generally, are only representative of the current uses of such doors.

In existing doors that swing vertically upward about axes having horizontal components, an increase in lifting force is required as the door and the axis of rotation approach lateral alignment. That is, the greatest lifting force is required to rotate the door further upward or to restrain the door from rotating further downward when the center of gravity of the door is neither above nor below the midpoint of the axis of rotation. This is true whether the door is rotated upward to open a laterally extending compartment or to close an overhead compartment. The increased force required to lift the door as the door is raised is a result of the increased force needed to overcome the increased torsional moment placed on the door by the weight of the door itself. This moment due to the weight of the door increases at the center of gravity of the door as the center of gravity increases in lateral deviation from vertical alignment with respect to the axis of rotation. The variable force required to rotate the door upward about the hinge axis detracts from the ease of manipulation and presents an undesirable feature to be considered before use of doors of this type is undertaken.

It is an object of this invention to make uniform the force required to rotate the door member of this invenice tion upward about an axis of rotation. The use of a constant force to rotate the door upward results in a more predictable speed of rotation and facilitates manipulation of the door member.

In a preferred embodiment of this invention, the door hinge is further comprised of a hydraulic damping device that prevents the door from swinging rapidly downward when it is released from a generally horizontal position. This damping device cushions the downward rotation of the door about the axis of rotation but does not restrict the upward rotation of the door member. This feature renders more predictable the downward rotational speed of the door and further facilitates manipulation of the door and further facilitates manipulation of the door member.

Since it is frequently desirable for an overhead door to be arrested at various points in its upward and downward rotational movement, other preferred embodiments incorporate a self-operative movement arresting means in the door hinge of this invention. This arresting means is comprised of a detent pin that latches in each of a series of apertures as the door member undergoes rotation. To arrest upward rotation, the forward surface of the detent pin is chamfered so that the detent pin is not restricted but cams through the apertures during downward movement of the door member. Upward rotation of the door member is prevented, however, when the detent pin is aligned with any of these apertures, since the detent pin locks against the aperture to prevent upward movement until it is released. Downward movement of the door may be prevented by provision of a shallow depression aligned with the detent pin. Movement of the door either upward or downward is prevented until enough force is applied to the door to force the detent pin out of the depression.

In a broad aspect this invention is a door hinge for governing the force required to rotate a door member upwards with respect to a frame member about an axis of rotation having a horizontal component comprising: an anchor means attached to one of said door and frame members; a swivel link means attached to the other of said door and frame members; a rotation means rotatably connecting said anchor means to said swivel link means at said axis of rotation; a spring biasing means extending from said anchor means parallel to and laterally spaced from said axis of rotation; a negator spring means rigidly attached to said swivel link means and extending linearly to said spring biasing means and beyond said spring biasing means to form an arc, and said negator spring means is concave with respect to said spring biasing means and said negator spring means is in tension and exerts a constant force on said spring biasing means and creates a moment on said door member aiding and inversely proportional to the moment on said door member due to the weight of the door, and both the moment on said door member due to the negator spring means and the moment on said door member due to the weight of the door vary inversely with respect to each other upon lateral deviation of the center of gravity of the door member from vertical alignment with said axis of rotation.

The construction and operation of this invention is more clearly illustrated by reference to the accompanying drawings.

FIG. 1 is a side elevational view in partial section of the door hinge of this invention.

FIG. 2 is a sectional view taken along the lines 2-2 of FIG. 1.

FIG. 3 is an isolated view of the detent pin of the embodiment of FIGS. 1 and 2.

FIG. 4 is a diagram illustrating the moments created due to the negator spring means of this invention.

Referring now to FIG. 1 there is shown a door hinge for governing the force required to rotate a door member 1 upwards with respect to a frame member about an axis of rotation P perpendicular to the plane of FIG. 1. An anchor means 2 is fastened flat up against a portion of the frame member 30 of this invention. The frame member 30 may be considered to be an interior side panel of an enclosure. The door 1 is illustrated in the closed position so that the door 1 blocks the opening of a compartment extending to the left in FIG. 1. The exterior face of the door member 1 is indicated at 33 while the interior face is indicated at '32.

The anchor means 2 is fastened to frame member 30 by means of screws 31. A swivel link means 3 is attached to the interior surface 32 of door member 1 by means of screws 7 extending through holes in a mounting plate 8. A rotation means rotatably connects the anchor means 2 to the swivel link means 3 at the axis of rotation P. The rotation means of the illustrated embodiment is comprised of a sleeve-like portion 6 of swivel link means 3 extending perpendicular to the plane of FIG. 1 and surrounding a central shaft 34 that protrudes out perpendicular from anchor means 2. Swivel link means 3 thereby rotates relative to anchor means 2. The movement of swivel link means 3 is facilitated by the provision of a lubricating fluid working between the shaft 34 and the sleeve 6.

-A spring biasing means also extends out from the anchor means 2 parallel to and laterally spaced from the axis of rotation P. The spring biasing means 5 is comprised of a central shaft 35 around which is positioned a bearing collar 36. Bearing collar 36 may easily be rotated about the shaft 35. A negator spring means 9 is rigidly attached to the swivel link means 3 by rivets 37. Negator spring means 9 extends linearly to the spring biasing means 5 and beyond to form an are 38. The negator spring means 9 is therefore concave with respect to the spring biasing means 5. The negator spring means 9 is always in tension throughout the movement of the door hinge and exerts a constant force on the spring biasing means 5. This force is indicated by the letter F in FIG. 4 acting at the point of contact K between the spring biasing means 5 and the negator spring means 9. The force F creates an equal opposing force on the door member 1 and a clockwise moment on the door member 1. This moment aids and is inversely proportional to the moment on the door member 1 due to the weight W of the door :at the center of gravity CG of the door as the door 1 is swung upward and counterclockwise about the axis of rotation P. In FIG. 1, it can be seen that in the closed position the center of gravity CG of the door is located in vertical alignment with the axis of rotation P. The moment on the door member 1 due to the weight of the door is minimized when the door is in this position since the weight of the door W has no moment arm with respect to the axis P. Conversely, the clockwise moment on the door member 1 due to the negator spring means 9 is at a maximum when the door member 1 is in the position shown in FIG. 1. This is because negator spring means '9 is in tension and exerts a lateral force F on the spring biasing means 5 and an equal opposing force on the door member 1 through the rivets 37 and screws 7 where the negator spring means 9 and the swivel link means 3 are anchored to the door member 1. The force on the door member 1 due to the negator spring means acts to the left through point K at a distance D from the axis of rotation P to exert a clockwise moment on the door member 1. FIG. 4 illustrates the reciprocal forces exerted on the spring biasing means 5. The distance D is the greatest moment arm at which the force on the door member acts throughout the upward rotation of door member 1. For this reason, the clockwise moment due to the negator spring means 9 is greatest when the door member 1 is in the position of FIG. 1. As the door member 1 is rotated counterclockwise about axis of rotation P, the center of gravity CG moves up and to the right and out of vertical alignment with the axis of rotation P. The weight of the door W thereby acts through a moment arm and exerts a clockwise moment on the door member 1. To compensate for the moment on door member 1 due to the weight W of the door, the moment on the door member 1 due to the negator spring means 9 is reduced. This occurs when the constant force of magnitude equal to force F acts through point K. It can be seen from FIG. 4 that the moment arm of this force is reduced to the length D which is smaller than the previous moment arm D. As the center of gravity CG rotates further upward and counterclockwise about the axis of rotation P, the clockwise moment on the door member 1 due to the weight W of the door member 1 continues to increase. As the clockwise moment on the door member 1 due to the weight W of the door member 1 at the center of gravity CG approaches its maximum value, the moment arm at which this force acts increases until the door member 1 has been rotated upward through an arc of At this time the center of gravity CG is neither above nor below the axis of rotation P and the force F due to the negator spring means 9 acts through a moment arm D", which is shorter than either of the distances D or D. When the clockwise moment on the door member 1 due to the weight of the door is at a maximum, the clockwise moment on the door member 1 due to the negator spring means 9 is at a minimum. This occurs when the door member 1 is rotated 90 counterclockwise from the position of FIG. 1. Conversely, when the clockwise moment on the door member 1 due to the weight of the door W is at a minimum, the clockwise moment on the door member 1 due to the negator spring means 9 is at a maximum. This condition occurs when the door member 1 is in the position of FIG. 1. The negator spring means 9 is chosen so that the decrease in the moment acting on the door member 1 due to the negator spring means throughout a 90 rotation of the door member is equal to the increase in the moment acting on the door member 1 due to the weight W of the door member as the door member rotates throughout the same arc. The net result is that a relatively constant force B may be applied to the door member to rotate the door member 1 counterclockwise 90 from the position shown in FIG. 1. The feature of requiring a constant force B to achieve upward rotation of the door member 1 facilitates immensely the ease of manipulating the door member of this invention. It can be seen that both the moment of the door member due to the negator spring means and the moment on the door member due to the weight of the door member vary inversely with respect to each other upon lateral deviation of the center of gravity CG of the door member 1 from vertical alignment with the axis of rotation P.

The door hinge illustrated is also comprised of a hydraulic damping means 12 interposed between the anchor means 2 and the swivel link means 3. The hydraulic damping means 12 is comprised of a cylinder 13 having a blind end 39 and an open end 40. The hydraulic damping means 12 is also comprised of a piston 41 reciprocally movable relative to and within the cylinder 13, and a piston shaft 16 fastened to the piston 41. The cylinder 13 is attached to the anchor means 2 at a pivot pin 14. The piston 41 and piston shaft 16 are attached to the swivel link means 3 by a fastening block 15. Alternatively, the cylinder 13 could be attached to the swivel link means 3 and the piston -41 and piston rod 16 could be attached to the anchor means 2. The hydraulic damping means 12 is further comprised of a cushion valve located at the piston 41 in cylinder 13. The cushion valve has a flexible gasket 19 with an annular rim protruding toward the blind end 39 of the cylinder 13. A rigid metal washer 43 secures the central portion of the gasket 19 while screw 20 fastens washer 43 and the gasket 19 to the piston 41. Through the washer 43, gasket 19, and piston 41 there is a passageway 42 providing an avenue of fluid communication between the two portions of the cylinder 13 on either side of the piston 41. Passageway 42 is sized small enough so that only a small amount of fluid can flow therethrough.

The cushion valve is located at the piston 41 in the cylinder 13 and allows easy movement of the piston 41 toward the open end 40 of the cylinder 13 while restricting movement of the piston toward the blind end 39 of cylinder 13. As the door member 1 rotates upward and counterclockwise about axis of rotation P, hydraulic fluid flows into the cavity of cylinder 13 adjacent to the blind end 39. The hydraulic fiuid flows through the passageway 42 and between the walls 17 of cylinder 13 and the annular rim of gasket 19. The hydraulic damping means 12 thereby presents no restriction to upward movement of the door member 1. When door member 1 is rotated downward back toward the position of FIG. 1, the hydraulic cushioning means 12 allows only a slow clockwise rotation of door member 1. Downward movement of the door member 1 is restricted since the rim of gasket 19 flares out and seals against the wall 17 of the cylinder 13, thereby restricting fluid flow to the passageway 42.

To obviate the problem of leakage through a seal around a moving piston shaft, a conventional hydraulic damping means has been modified in this invention to include a flexible diaphragm 1:8 sealed either to the piston shaft 16 at the piston 41 or to the piston 41 at the shaft 16. Flexible diaphragm 18 is also circumferentially sealed to the cylinder 13, preferably at the open end 40 of cylinder 13. A quantity of hydraulic fluid 43 is trapped between the cylinder 13 and the diaphragm 18 on both sides of the piston 41. Besides obviating the requirement for a fluid tight seal at aperture 45 in closure disk 46, the use of flexible diaphragm 18 in the hydraulic cushioning device 12 has another advantage. In many conventional hydraulic cushioning devices not utilizing a separate reservoir of flexible volume, the cushioning action is uneven as the piston is forced into the cylinder. This variation in cushioning in a hydraulic cushioning device of rigid dimensions occurs because of the area occupied by the piston shaft. That is, as a piston travels through a cylinder, it displaces a certain amount of hydraulic fluid. If this fluid flows past the piston into that portion of the cylinder containing the piston shaft, there is less volume available which the hydraulic fluid may occupy. This decrease in volume is equal to the volume occupied by the piston shaft over the length of the piston displacement. Pressure is built up in the cylinder adjacent to the piston shaft and further longitudinal displacement of the piston toward the blind end of the cylinder is resisted. The same effect holds true when the piston is withdrawn, since there is more volume available at the blind end of the cylinder than there is hydraulic fluid displaced from adjacent the piston shaft. The result of this conventional construction is a hydraulic cushioning device in which the damping is much larger when the damping device is in the compressed state and when it is in the expanded state than 'when it is in an intermediate state, since the hydraulic fluid is normally nearly incompressible.

In the present invention, the flexible diaphragm 18 moves radially inward toward the piston shaft 16 as the piston 41 moves toward the blind end 39 of the cylinder 13. This radially inward movement provides additional space to accommodate the excess hydraulic fluid displaced from the area of the cylinder near blind end 39. Conversely, when the piston 41 is withdrawn toward the open end 40 of cylinder 13, the flexible diaphragm 18 expands radially outward toward the walls 17 of cylinder 13. This allows additional hydraulic fluid to be made available to fill the extra space vacated in the area of cylinder 13 adjacent to the blind end 39. Due to the adjustable volume of the hydraulic damping means 12, hydraulic damping means 12 is provided with a relatively constant damping characteristic. Door member 1 may thereby move clockwise downward to the position of FIG. 1 at a uniform rate.

A further feature of the hinge illustrated allows the swivel link means 3 to be arrested in its relative downward clockwise movement with respect to anchor means 2. A detent pin 25 is carried by swivel link means 3 and is spaced at a lateral distance from the axis of rotation P.

The anchor means 2 has a surface 26 adjacent to the swivel link means 3 and penetrated by apertures 10 and 11. The apertures 10 and 11 are spaced laterally from the axis of rotation P at the same distance as is detent pin 25. Detent pin 25 has an engaging end 46 with a forward surface 47 with reference to the direction of relative rotation between the anchor means 2 and the swivel link means 3 as the door member 1 is rotated downward. That is, the forward surface 47 is the first surface of the detent pin 25 to contact the apertures 11 and 10 when the door member 1 is rotated clockwise downward about axis of rotation P. The forward surface 47 is chamfered so that the detent pin 25 cams through each aperture 10 as the door member is rotated downward. A detent pin spring 49 biases the detent pin 25 toward the anchor means 2. This drives the engaging end 46 of the detent pin 25 into engagement with the apertures 10 and 11 as the detent pin 25 becomes aligned with these apertures. During the downward movement of door member 1, the chamfered surface 47 of the detent pin 25 allows the detent pin to cam through the apertures 10 'without resistance to the movement of door member 1. When an attempt is made to raise door member 1 from the closed position illustrated in FIG. 1, however, the detent pin 25 is engaged in one of the apertures 10 and arrests the upward rotation of swivel link means 3 with respect to anchor means 2 as despite any force exerted in an attempt to move the door member 1 upward in a counterclockwise direction about axis of rotation P. The same will also be true whenever detent pin 25 is engaged in any of the other apertures 10.

The apertures 10 are perforations extending entirely through the anchor means 2. When the engaging end 46 of the detent pin 25 reaches an aperture 10 during upward movement of door member 1, engaging end 46 is sprung into a locking engagement with that aperture 10. A counterclockwise push on the door member is insuflicient to release the detent pin 25, and detent pin 25 must be forced out of engagement with the apertures 10 in order for upward motion to continue. This disengaging force is supplied through the use of an L-shaped lever member 29. A pivot pin 48 rotatably attaches lever member 29 to detent pin housing 27, which in turn is welded to swivel link means 3. A remote unlocking means (not shown) is connected to the detent pin 25 by cord 22 to overcome the bias of the detent pin spring '49. The bias is overcome upon actuation of the remote unlocking means which results in tension on cord 22. Cord 22 pulls leg 23 of lever member 29. Leg 24 of lever member 29 thereby forces detent pin 25 back from engagement in the apertures by overcoming the spring bias of detent pin spring 49. The detent pin 25 is thereby prevented from engaging any of the apertures until deactuation of the conventional remote unlocking device. Actuation of the remote unlocking device thereby permits door member 1 to rotate counterclockwise upward to a closed position.

Aperture 11 is not a perforation but is a shallow depression in the anchor means 2 that arrests movement of the door member 1 in both upward and downward directions of rotation. A slight clockwise push on door member 1 will overcome the arrest of motion at depression 11 on door member 1 and will allow the door member 1 to continue rotating clockwise downward. Similarly, a slight increase in a counterclockwise force will allow door member 1 to be rotated past aperture 11 to a fully opened position.

The foregoing detailed description and illustrations of the preferred embodiment of this invention have been given for clearness of understanding only, and no unnecessary limitations should be construed therefrom as other modifications will be obvious to those skilled in the art. For example, the mounting of the detent pin 25 upon the anchor means 2 and the provision of corresponding apertures in the swivel link means 3 is an obvious modification and is included within the scope of the invention disclosed herein.

We claim as our invention:

1. A door hinge for governing the force required to rotate a door member upwards with respect to a frame member about an axis of rotation having a horizontal component comprising:

(a) an anchor means attached to one of said door and frame members;

(b) a swivel link means attached to the other of said door and frame members;

() a rotation means rotatably connecting said anchor means to said swivel link means at said axis of rotation;

((1) a spring biasing means extending from said anchor means parallel to and laterally spaced from said axis of rotation;

(e) a negator spring means rigidly attached to said swivel link means and extending linearly to said spring biasing means and beyond said spring biasing means to form an arc, and said negator spring means is concave with respect to said spring biasing means and said negator spring means is in tension and exerts a constant force on said spring biasing means and creates a moment on said door member aiding and inversely proportional to the moment on said door member due to the weight of the door, and both the moment on said door member due to the negator spring means and the moment on said door member due to the weight of the door member vary inversely with respect to each other upon lateral deviation of the center of gravity of the door member from vertical alignment with said axis of rotation.

2. The door hinge of claim 1 further comprising a hydraulic damping means interposed between said another means and said swivel link means and said hydraulic damping means is comprised of a cylinder having a blind end and an open end attached to one of said anchor means and swivel link means, a piston reciprocally movable relative to and within said cylinder, a piston shaft fastened to said piston and attached to the other of said anchor means and swivel link means, a cushion valve located at said piston in said cylinder allowing movement of said piston in one direction relative to said cylinder and restricting movement of said piston relative to said cylinder in an opposite direction, a flexible diaphragm sealed to said piston shaft at said piston and circumferentially sealed to said cylinder, and hydraulic fluid trapped between said cylinder and said diaphragm.

3. The door hinge of claim 1 further comprising a hydraulic damping means interposed between said anchor means and said swivel link means and said hydraulic damping means is comprised of a cylinder having a blind end and an open end attached to one of said anchor means and swivel link means, a piston reciprocally movable relative to and within said cylinder, a piston shaft fastened to said piston and attached to the other of said anchor means and swivel link means, a cushion valve located at said piston in said cylinder allowing movement of said piston 5 in one direction relative to said cylinder and restricting movement of said piston relative to said cylinder in an opposite direction, a flexible diaphragm sealed to said piston at said piston shaft and circumferentially sealed to said cylinder, and hydraulic fluid trapped between said cylinder and said diaphragm.

4. The door hinge of claim 1 further characterized in that a detent pin is carried by a first of said anchor means and said swivel link means and is spaced at a lateral distance from said axis of rotation, and a second of said anchor means and said swivel link means has a surface adjacent to said first means penetrated by at least one aperture spaced laterally from said axis of rotation the same distance as is said detent pin, and said detent pin has an engaging end with a forward surface, with reference to the direction of relative rotation between said anchor means and said swivel link means as said door member is rotated downward, and said forward surface is chamfered whereby said detent pin cams through each aperture as said door member is rotated downward, and a detent pin spring biases said detent pin toward said second means thereby driving said engaging end of said detent pin into engagement with said apertures and arresting said means attached to said door member with respect to said means attached to said frame member against upward rotation of said door member.

5. The door hinge of claim 4 further characterized in that at least one of said apertures is a shallow depression in said second means and also arrests said means attached to said door member with respect to said means attached to said frame member against downward rotation of said door member.

6. The door hinge of claim 4 further comprising a remote unlocking means connected to said detent pin to overcome, upon actuation, the bias of said detent pin spring and thereby disengage said detent pin from said apertures.

References Cited UNITED STATES PATENTS FRANCIS K. ZUGEL, Primary Examiner P. A. ASCHENBRENNER, Assistant Examiner US. Cl. X.R. 

